Dabigatrane etexilate is known in the art and was first disclosed in International patent application WO 98/37075. Processes for the manufacture of dabigatran etexilate are also known from WO 2006/000353 or Hauel et al. (J. Med. Chem, 2002, 45, 1757 ff).
According to Hauel et al 1 can be obtained from nitro-compound of formula 2 via hydrogenation on Pd/C.

However, in particular in large-scale processes the reaction occasionally stops due to catalyst poisoning which leads to an incomplete turnover of the starting material. This can require further addition of catalyst during the course of the reaction. Moreover, reaction time is prolonged which has a negative influence on the quality of the reaction product 1. The process for manufacture of 2 is for instance disclosed in Hauel et al (J. Med. Chem, 2002, 45, 1757-1766). From the synthesis of 2 as disclosed in Hauel et al., it is apparent that process related sulfur impurities might be carried over into 2 with varying amounts. These impurities strongly influence the reaction time, quality and catalyst consumption in the manufacture of 1.
Therefore, it is the object of the invention to provide for an improved process for the manufacture of 1 which overcomes the foregoing deficiencies that are associated with catalyst poisoning.